On Tuesday night's Republican presidential debate and again on Wednesday morning, GOP candidate Donald Trump touted the controversial 1950s "Operation Wetback" program as a way of dealing with the nation's approximately 11 million immigrants currently without legal status.

Under the then-President Dwight D. Eisenhower program, immigrants inside the U.S. were rounded up and deported to remote places, resulting in deaths and criticism that it led to human rights abuse.

"The Eisenhower mass deportation policy was tragic," said Aguilar. "Human rights were violated, people were removed to remote locations without food and water, there were many deaths, sometimes U.S. citizens of Hispanic origin were removed. It was a travesty — it was terrible. To say it's a success story, it's ridiculous."

Though Trump extolled the program's praises on the GOP debate, he didn't call "Operation Wetback" by name. The term "wetback" is considered a slur.

"I'm just shocked he didn't come out and say it," said University of Maryland political scientist Stella Rouse.

Yet she said it was very clear what Trump was advocating.

"It's unbelievable, but he and the people who support his attitude are more and more comfortable expressing it in different ways — with impunity," said Rouse. "If you're racist and nativist that's what gets rewarded without any specificity or viability of how do these things happen. It's amazing."

Like Aguilar, Rouse said in an interview with NBC News that regardless of whether people agree with "sending back" immigrants, the 1950s program has been widely criticized for human rights abuses, among them shaving the heads of Mexicans so the Border Patrol could recognize them if they were trying to come back through the border or Attorney General Herbert Brownell's comments to "shoot" Mexicans on site if they attempted to cross the border.

Beyond the issues of human rights, scholars have debated the program's effectiveness. Some have questioned whether the numbers cited in Operation Wetback — the deportation of about 1 million people — are accurate.

"Even if you buy the fact that 1 million were deported it's not even close to the 11 million immigrants we have in this country," said Rouse.

Trump was asked on Wednesday during "Morning Joe" how he would deport 11 million people, and he said he would have a "deportation force" that would do it humanely; he repeated the statement to NBC's Katy Tur.

"It's not possible economically," said Aguilar, citing the resources needed to round up and deport 11 million people. "And it's not the American way," added Aguilar on NPR.

But Trump's lack of specifics has been a hallmark of the campaign, said Rouse. For now, said Rouse, accuracy and a reality check are not what presidential hopefuls like Trump are after.

"He's appealing to a segment of the GOP electorate that agrees with him," said Rouse. "I think he wrote his ticket off the general election by invoking Eisenhower's Operation Wetback, but it's a winning strategy to bring out some primary voters."